Non LBC Engine Question.

["Jerry Goulet" <jgoulet@thomsontechnology.com>]

The engine on my garden tractor (20 hp) starts and runs at full choke pull, but 
as the choke is pushed in gradually after a few moments of running the engine 
starts to die and will die if pushed in fully.  What would cause the engine to 
run reasonably well at partial choke but not at no choke ?

Jerry Goulet
60 TR3A
95 SEARS